You have the Emotions of Meliodas, that just injured the DK, and said they will return to their body ones they leave purgatory.

Also there is no need to stand against an Emotionless Meliodas, he is Emotionless but that's all he isn't just suddenly gonna slaughter everyone.

His only goal is to collect the commandments and break the curse, as long as they don't fight him he wont fight them and he doesn't want to kill them, just like he personally didn't attack Arthur back then and even told him to just run so he doesn't get injured.

Most seem to misunderstand it even in universe but the battle against Meliodas is no "we have to stop him for the good of the land/people/world" but a "we don't want to loose him so we want to stop him", Meliodas himself has no intention to do anything to anyone as long as he can break the curse.